Rotating sprinklers used in agricultural irrigation are often configured to include a stationary nozzle that emits a stream onto a rotating water-deflection plate formed with one or more generally radially-oriented grooves that serve to redirect the stream radially outwardly in a desired pattern. Typically, the plate is supported on one or more support struts fixed to and extending from the sprinkler body, so that the stream or streams thrown outwardly by the water-deflection plate must rotate past the support struts. This arrangement has two disadvantages. One is that the struts cause dry areas in the sprinkling pattern, and the other is that the water striking the support struts drips off the sprinkler and pools in the area directly beneath. Thus, depending on the specific operating parameters, the sprinkler may underwater in some areas and overwater in others, degrading overall performance.
It is also by now a conventional practice to use rotating sprinklers with braking mechanisms that retard the rotation of the water-deflection or distribution plate in order to maximize the throw radius of the sprinkler by eliminating the “horsetail” effect prevalent with free-spinning sprinklers. In some instances, this arrangement can exacerbate the problems noted above due to the slower rotation of the water-deflection plate. In addition, thrust loading on internal components can cause excessive mechanical friction, possibly leading to reduced service life.
There remains a need, therefore, for a braked sprinkler with enhanced performance and a sprinkler that eliminates or at least substantially minimizes drool or drip-off.